1. Field of the Invention
The invention relates generally to the determination of proper X-ray exposures in connection with producing radiographs and more particularly to a computer usable by technicians for determining the proper X-ray exposure settings of an X-ray machine with facility and accuracy.
2. Description of the Prior Art
Problems related to technique selection of X-ray exposures in connection with the production of a quality radiograph are well known and include obtaining quality radiographs regardless of the patients size or age, obtaining consistent radiographs regardless of the machine being used or the technologist using the machine, the difficulty of using correction factors, especially when several are used at once, and the inability to use any kilovoltage, milliamperage, or time the situation or radiologist may require.
Generally it is desired to produce substantially the same density radiograph for exposures of different anatomical parts and parts of different thicknesses. Different anatomical parts have different thicknesses and thus require different exposures for obtaining the same radiograph density. The prior art teaches there is one thickness-to-exposure relationship for the entire body which is linear for obtaining the same radiograph density, but this axiom has been found to be erroneous in connection with the achievement of the present invention.
Manually operable computers, or more specifically slide rules, are known and used to some extent in connection with the determination of the exposure settings of an X-ray machine for a given tissue thickness or anatomical part. However, such slide rules have been found to be not only cumbersome and inaccurate but not applicable to all X-ray machines.